In Situ Endoscopic Analysis of Vascular Supply and Regenerated Alveolar Bone in β -TCP Grafted and Ungrafted Postextraction Sites before Implant Placement: A Prospective Case Control Study

Abstract

Background. Endoscopy has seen a significant development over recent years in various medical fields with its application expanding from the support of minimal invasive surgery to in situ imaging. In this context, the application of endoscopic techniques to assess the quality of the regenerated bone in situ in the drill hole before implant placement is an appealing approach. Aim. The aim of this study was to use short distance support immersion endoscopy (SD-SIE) to compare the quality of regenerated bone in healed postextraction sites, which are grafted with an in situ hardening β-TCP, against ungrafted sites, before implant placement. This assessment was based on microscopic bone analysis in combination with the blood vessel count. Method. 13 spontaneously healed and 13 grafted postextraction sites in 3 men and 6 women, aged 26-83 years, were evaluated using SD-SIE after 4-6 months. SD-SIE was applied in drill holes before implant placement, and videos were taken from representative central buccal areas. The video recordings were analyzed using Image J software for (1) number of blood vessels per area (NBV), (2) relative area of vessels (VA), (3) relative area of mineralized bone (MBA), (4) relative area of unmineralized bone (UMBA), and (5) relative area of bone substitute (BSA). Results. The grafted sites showed more (1) NBV as well as (2) VA (8.6 ± 1.1; 2.03 ± 0.28%) than the ungrafted sites (2.5 ± 0.6; 1.18 ± 0.36%) (independent t-test; p<0.05); (3) MBA and (4) UMBA were similar to those in the grafted sites (86.3 ± 2.2 %; 13.7 ± 2.2 %) and to the ungrafted sites (89.5 ± 3.7%; 10.5 ± 3.6%) (independent t-test; p>0.05); and (5) BSA in the grafted sites was 18.2 ± 5.4%. Conclusion. SD-SIE is an interesting new approach for in situ assessment of bone quality and blood supply before implant placement. The regenerated bone in β-TCP grafted extraction sockets showed an increased vascularization compared to ungrafted sites providing a vital support for subsequent implant placement.